This invention relates to a pager or paging receiver for use in a paging system. More particularly, the pager receiver is of the type which is not only for informing the user of a call but also is capable of displaying a message or the like.
While carried by the user movable within a service area of a paging system and rendered active or operative, a pager receiver must always be ready for detecting a call which may reach that pager receiver at any time from a transmitting station of the system on a radio calling signal. The power for use in receiving the radio calling signal and indicating the call, is supplied from a battery carried by the receiver.
In order to reduce the power consumption in the receiver, it is customary to resort to the battery saving scheme as called in the art. According to the scheme, pager receivers of the paging system, either rendered active or kept inactive, are divided into a predetermined number of groups. Each frame of the radio calling signal is divided into a plurality of subframes which are allotted to the respective groups as will later be described with reference to a few figures of the accompanying drawing. A conventional pager receiver for use in such a paging system comprises a receiver circuit for receiving the radio calling signal and for detecting a calling code preassigned to the receiver under consideration and an on-off control circuit for automatically energizing the receiver circuit only during the subframe allotted to the group which includes the receiver in question.
On the other hand, it is a recent trend to make the radio calling signal include a message code which accompanies the calling code for a pager receiver and is representative of a message to be conveyed to that pager receiver. An example of such a pager receiver is disclosed by Alfred B. Levine in U.S. Pat. No. 4,336,524. The subframe becomes accordingly long. As will become clear as the description proceeds, it has now been found possible to unexpectedly save the battery in such a pager receiver.